Introduction: The emergence and spreading of Rifampicin-resistance strains of mycobacterium tuberculosis pose significant challenges to tuberculosis control programs in resource-limited countries like Ethiopia. This study aimed to assess the proportion and factors associated with primary rifampicin resistance. Methods: A facility-based cross-sectional study was conducted from April to November 2019 among 570 new pulmonary tuberculosis patients. A systematic random sampling technique was used to select the study participants from 8 Gene-Xpert testing hospitals. Rifampicin resistance was detected by Gene-Xpert assay from sputum specimens. Data were collected by face-to-face interviews, document review, and laboratory results using a pre-tested structured questionnaire. We developed the questionnaire from different kinds of literature and the World Health Organization resources. Variables with P-value <0.2 in simple binary logistic regression were included in the multiple binary logistic regressions. A statistical test was reported as significant when p-value < 0.05 in multiple variable logistic regressions. Fitness of goodness was checked by using the Hosmer Lemeshow model fitness test. Results: A total of 570 individuals have participated in this study. Of those, 43 (7.50%) 95% CI: 5-10) were resistant to rifampicin. Persons, have a contact history with known tuberculosis Patients (AOR 2.5 [95% CI: 1.21-5.11]), with human immune virus infection (AOR 2.3 [95% CI: 1.11-4.73]) and being diabetic Mellitus cases (AOR 4.2[95% CI: 1.51-8.78]) were factors significantly associated with rifampicin resistance. Conclusions and recommendations: The proportion of rifampicin resistance was high. Identified factors significantly associated with rifampicin resistance were persons having contact history with known tuberculosis patients, human immune virus infection, and being diabetic Mellitus cases. Strengthen the prevention of rifampicin resistance tuberculosis transmission, strengthening contact tracing, improve TB/HIV coinfection health care services, and screening tuberculosis patients for diabetic Mellitus is crucial.